1. Field
Embodiments relate to a secondary battery.
2. Description of the Related Art
In a secondary battery, an electrode assembly including a positive electrode plate, a negative electrode plate, and a separator is positioned into a can formed of a metal material. An electrolyte is also injected into the can to seal the inside of the can. A secondary battery generally includes an electrode terminal electrically insulated from a can on an upper side thereof. The electrode terminal becomes one pole of the battery, and the can itself becomes the other pole.
Battery safety devices such as a secondary protection device, for example, a positive temperature coefficient (PTC) device, and a protective circuit module are connected to the sealed secondary battery to form a battery pack. Here, the safety devices are respectively connected to a positive electrode and a negative electrode to stop current flow when the voltage of the battery is suddenly increased due to overheat or over-charge/over-discharge of the battery, thereby reducing the risk of the battery exploding.
As the usage of mobile devices is increasing, there is an increasing need to improve the capacity of the battery without significantly increasing its size.